摘要 |
1399773 Packages TETRA PAK DEVELOPPEMENT SA 13 Feb 1973 [14 March 1972] 6986/73 Heading B8C A packing container formed from a thermoplastics-coated web has two sealing joints such as 40, 41 crossing each other, at least one being a sealing fin in which the web is joined inside to inside, and a tear-strip 22 is placed underneath or near the inside of the fin with a part of the strip 22 accessible from the exterior. Strip 22 comprises a thread which may be of plastics and is coated with a similar thermoplastics to that of the container web. Alternatively, a multi-strand thread, or a flat strip, suitably coated, may be used. The containers are formed by heat-sealing longitudinal edges of the web to form a tube, with transverse welding and severing to form containers which may be tetrahedral or parallelepipedic. Strips 22 are attached to the web beforehand in a repeated pattern; several examples are given. |